Ziprasidone

Identification

Name

Ziprasidone

Accession Number

DB00246 (APRD00540)

Type

Small Molecule

Groups

Approved

Description

Ziprasidone (marketed as Geodon, Zeldox) was the fifth atypical antipsychotic to gain FDA approval (February 2001). Ziprasidone is Food and Drug Administration (FDA) approved for the treatment of schizophrenia, and the intramuscular injection form of ziprasidone is approved for acute agitation in schizophrenic patients. Ziprasidone has also received approval for acute treatment of mania associated with bipolar disorder. [Wikipedia]

Ziprasidone is a psychotropic agent belonging to the chemical class of benzisoxazole derivatives and is indicated for the treatment of schizophrenia. Ziprasidone is a selective monoaminergic antagonist with high affinity for the serotonin Type 2 (5HT2), dopamine Type 2 (D2), 1 and 2 adrenergic, and H1 histaminergic receptors. Ziprasidone acts as an antagonist at other receptors, but with lower potency. Antagonism at receptors other than dopamine and 5HT2 with similar receptor affinities may explain some of the other therapeutic and side effects of Ziprasidone. Ziprasidone's antagonism of muscarinic M1-5 receptors may explain its anticholinergic effects. Ziprasidone's antagonism of histamine H1 receptors may explain the somnolence observed with this drug. Ziprasidone's antagonism of adrenergic a1 receptors may explain the orthostatic hypotension observed with this drug. Ziprasidone functions as an antagonist at the Dopamine D2 , 5HT-2A , and 5HT-1D receptors, and as an agonist at the 5HT-1A receptor. Ziprasidone also inhibits synaptic reuptake of serotonin and norepinephrine.

Mechanism of action

Ziprasidone's antipsychotic activity is likely due to a combination of its antagonistic function at D2 receptors in the mesolimbic pathways and at 5HT2A receptors in the frontal cortex. Alleviation of positive symptoms is due to antagonism at D2 receptors while relief of negative symptoms are due to 5HT2A antagonism.

Ziprasidone is extensively metabolized after oral administration with only a small amount excreted in the urine (<1%) or feces (<4%) as unchanged drug.
Approximately 20% of the dose is excreted in the urine, with approximately 66% being eliminated in the feces.